import Tools from '../tools';

function mergeConfig(defaultConfig, instanceConfig = {}) {
  const CONFIG_KEY_LIST = ['url', 'method', 'data', 'dataType', 'responseType', 'params', 'isProxy'];
  const CONFIG_MERGE_DEEP_KEY_LIST = ['header'];
  const CONFIG_OPTIONAL_KEY_LIST = ['baseURL'];
  const CONFIG_ALL_KEY_LIST = [...CONFIG_KEY_LIST, ...CONFIG_MERGE_DEEP_KEY_LIST, ...CONFIG_OPTIONAL_KEY_LIST];
  const ARGS_ALL_KEY_LIST = [...new Set([...Object.keys(instanceConfig), ...Object.keys(defaultConfig)])];
  const REMAINDER_KEY_LIST = ARGS_ALL_KEY_LIST.filter(key => !CONFIG_ALL_KEY_LIST.includes(key));
  let newConfig = {}

  // 必要参数
  CONFIG_KEY_LIST.forEach(prop => {
    const val = instanceConfig[prop] || defaultConfig[prop];

    !Tools.isType('Undefined', val) && (newConfig[prop] = val);
  });

  // 必要深拷贝参数
  CONFIG_MERGE_DEEP_KEY_LIST.forEach(prop => {
    const defaultVal = defaultConfig[prop];
    const instanceVal = instanceConfig[prop];

    if (Tools.isType('Object', instanceVal)) {
      newConfig[prop] = Tools.deepCopy(defaultVal, instanceVal);
    } else if (Tools.isType('Object', defaultVal)) {
      newConfig[prop] = Tools.deepCopy(defaultVal);
    }
  });

  // 配置文件中可选参数
  CONFIG_OPTIONAL_KEY_LIST.forEach(prop => {
    const val = defaultConfig[prop];

    if (!Tools.isType('Undefined', val)) {
      newConfig[prop] = defaultConfig[prop];
    }
  });

  // 合并未出现在上述列表中的参数
  REMAINDER_KEY_LIST.forEach(prop => {
    const defaultVal = defaultConfig[prop];
    const instanceVal = instanceConfig[prop];

    if (!Tools.isType('Undefined', instanceVal)) {
      newConfig[prop] = instanceVal;
    } else if (!Tools.isType('Undefined', defaultVal)) {
      newConfig[prop] = defaultVal;
    }
  });

  newConfig.instanceURL = instanceConfig.url;
  newConfig.url = Tools.getFullURL(newConfig.baseURL, newConfig.url);
  newConfig.url = Tools.paramsToURL(newConfig);
  newConfig.header = Tools.adapterContentType(defaultConfig.header, instanceConfig.header, newConfig.header);

  if (newConfig.method.toLowerCase() == 'upload') {
    delete newConfig.header['content-type'];
  }

  return newConfig;
}

export default mergeConfig;
